In the computer aided design of printed circuit boards the pattern of conductor or interconnect between points to be wired together through one or more layers is typically accomplished using an automated routing or "maze runner" algorithm. Such a system builds an expanding data base or map of available locations where conductor pattern may be run from one of the points of the set of points to be connected until the map of available locations expands to include the other point (or points) of that set. Various algorithmic processing techniques are available commercially to accomplish this function. In order to insure that certain printed circuit board criteria are met, the automated routing systems will operate according to an interconnect protocol which specifies certain constraints upon the conductor pattern between points, such as minimal conductor size, minimal conductor spacing, number of acceptable vias, or layer to layer connection paths, and total conductor length. These protocols may be global to the entire printed circuit board or vary with each set of points to be interconnected. As typically happens, particularly in the design of complex, multi-layered circuit boards, after automated routing has processed the entire list of sets of points to be interconnected, several sets will have been found not possible to interconnect utilizing the automated routing system under the protocols provided for that printed circuit board.
Once the list of sets of points that cannot be automatically interconnected is established, a human operator must take over the task of manually interconnecting those sets of points. It should be noted that it is a very time consuming and frustrating process for an operator to manually interconnect the sets of points which were left by the automatic routing system.